Letter from Joseph Ernest Petavel, The University, Manchester, to Dr Dugald Clerk, 57, 58 Lincoln's Inn Fields, London Thanking Clerk for O'Gorman's report on 'darts' which he returns; he is glad to hear that the 'Artful Dodger' is progressing well. Gives news of progress with trench mortars and mine sweeps. 24 March 1915